In a simple construction, a conventional color negative film intended for in-camera exposure typically takes the following form:
______________________________________ CNF-I ______________________________________ OC BRELU YFL GRELU IL RRELU AHL TRANSPARENT FILM SUPPORT ______________________________________
On the transparent film support are coated in the order shown, a series of processing solution penetrable hydrophilic colloid layers: antihalation layer AHL, a red recording emulsion layer unit RRELU containing a red sensitized silver iodobromide (AgIBr) emulsion and a colorless cyan dye-forming coupler, an interlayer IL containing an oxidized developing agent scavenger, a green recording emulsion layer unit GRELU containing a green sensitized AgIBr emulsion and a colorless magenta dye-forming coupler, a yellow filter layer YFL containing a Carey Lea silver or a processing solution decolorizable yellow filter dye and an oxidized developing agent scavenger, a blue recording emulsion layer unit BRELU containing blue sensitive (optionally blue sensitized) AgIBr emulsion and a colorless yellow dye-forming coupler, and a transparent protective overcoat OC. In the simplest possible construction capable of producing a color negative image, all of the hydrophilic colloid layers, except BRELU, GRELU and RRELU can be omitted. In the overwhelming majority of practical applications all of the layers of CNF-I described above are employed and, most commonly, many additional addenda are incorporated for performance enhancement. For example, comparatively small amounts of colored counterparts of one or more of the colorless yellow, magenta and cyan dye-forming couplers are commonly employed as masking couplers.
Yellow, magenta and cyan dye-forming couplers can take varied forms. Colorless dye-forming couplers are relied upon for forming yellow, magenta and cyan dye images, as illustrated by Research Disclosure, Item 38957, X. Dye image formers and modifiers, B. Image-dye-forming couplers and C. Image dye modifiers. Specific illustrations of colorless cyan dye-forming 2-(alkoxyarylcarbamoyl)-1-naphthol couplers are provided by Vanden Eynde et al U.S. Pat. No. 3,488,193 and Kobayashi et al U.S. Pat. No. 4,957,853.
In their simplest possible construction each of BRELU, GRELU and RRELU contain a single AgIBr emulsion. However, as elaborated on in Research Disclosure, Vol. 389, September 1996, Item 38957, I. Emulsion grains and their preparation, E. Blends, layers and performance categories, paragraph (7), when a fast emulsion layer is coated over a slow emulsion layer, an increase in imaging speed without an offsetting increase in granularity can be realized. Therefore, it is common practice to double-coat or triple-coat by splitting the AgIBr emulsions in BRELU, GRELU and RRELU into two or three separate emulsion layers differing in imaging speed.
A typical double-coated color negative film construction can take the following form:
______________________________________ CNF-II ______________________________________ OC BRELU Fast blue recording emulsion layer Slow blue recording emulsion layer YFL GRELU Fast green recording emulsion layer Slow green recording emulsion layer IL RRELU Fast red recording emulsion layer Slow red recording emulsion layer AHL TRANSPARENT FILM SUPPORT ______________________________________
It is also common practice to space physically the fast and slow emulsion layers that record blue, green or red to minimize the number of slow emulsion layers that must be penetrated by exposing radiation to reach the fast green and/or fast red emulsion layers. Two common constructions are illustrated by the following:
______________________________________ CNF-III ______________________________________ OC Fast BRELU IL Fast GRELU IL Fast RRELU IL Slow BRELU YFL Slow GRELU IL Slow RRELU AHL TRANSPARENT FILM SUPPORT ______________________________________
and
______________________________________ CNF-IV ______________________________________ OC BRELU YFL Fast GRELU IL Fast RRELU IL Slow GRELU IL SIow RRELU AHL TRANSPARENT FILM SUPPORT ______________________________________
The Kodak Flexicolor.TM. C-41 process is commonly employed for processing imagewise exposed color negative films. Since minor adjustments of the C-41 process are undertaken from time to time, the following detailed description is provided:
______________________________________ Develop 3'15" Developer 37.8.degree. C. Bleach 4' Bleach 37.8.degree. C. Wash 3' 35.5.degree. C. Fix 4' Fixer 37.8.degree. C. Wash 3' 35.5.degree. C. Rinse 1' Rinse 37.8.degree. C. Developer Water 800.0 mL Potassium Carbonate, anhydrous 34.30 g Potassium bicarbonate 2.32 g Sodium sulfite, anhydrous 0.38 g Sodium metabisulfite 2.96 g Potassium Iodide 1.20 mg Sodium Bromide 1.31 g Diethylenetriaminepentaacetic acid 8.43 g pentasodium salt (40% soln) Hydroxylamine sulfate 2.41 g N-(4-amino-3-methylphenyl)-N-ethyl- 4.52 g 2-aminoethanol Water to make 1.0 L pH @ 26.7.degree. C. 10.00 +/- 0.05 Bleach Water 500.0 mL 1,3-Propylenediamine tetra- 37.4 g aceticacid 57% Ammonium hydroxide 70.0 mL Acetic acid 80.0 mL 2-Hydroxy-1,3-propylenediamine 0.8 g tetraacetic acid Ammonium Bromide 25.0 g Ferric nitrate nonahydrate 44.85 g Water to make 1.0 L pH 4.75 Fix Water 500.0 mL Ammonium Thiosulfate (58% solution) 214.0 g (Ethylenedinitrilo)tetraacetic acid 1.29 g disodium salt, dihydrate Sodium metabisulfite 11.0 g Sodium Hydroxide (50% solution) 4.70 g Water to make 1.0 L pH at 26.7.degree. C. 6.5 +/- 0.15 Rinse Water 900.0 mL 0.5% Aqueous p-tertiary-octyl-(.alpha.- 3.0 mL phenoxypolyethyl)alcohol Water to make 1.0 L ______________________________________
Koboshi et al U.S. Pat. No. 4,937,178 discloses a process of producing a color negative image having a magenta dye density equal to at least 2 during a development time of not more than 3 minutes employing an imagewise exposed color negative film that produces a magenta dye density of less than 2 during development under conditions essentially similar to the Flexicolor.TM. C-41 process described above. To get higher magenta dye densities in a shorter development time "unconventionally active conditions" are employed. Reduced graininess is stated to be an unexpected advantage of unknown origin. Numerous specific preferred selections within the generic process are stated to be separate inventions. A listing of 99 colorless cyan dye-forming couplers and 38 colored cyan dye-forming couplers taught to be useful by Koboshi et al includes only phenolic cyan dye-forming couplers, while in the Examples 1-hydroxy-4-(.beta.-methoxyethylaminocarbonylmethoxy)-N-.delta.-(2,4-di-t -amylphenoxy)butyl!-2-naphthamide is employed as a colorless coupler in only "standard" (comparison) color negative films, although lesser amounts of the colored coupler 1-hydroxy-4-4-(1-hydroxy-8-acetamido-3,6-disulfo-2-naphthylazophenoxy!-N- .delta.-(2,4-di-t-amylphenoxy)butyl!-2-naphthamide are employed throughout the Examples. From this it is apparent that Koboshi et al did not consider colorless naphthol cyan dye-forming couplers to be advantageous in the process disclosed.